1. Field of the Invention
The invention relates to an engine block having at least one cooling duct extending in an intermediate wall between the cylinders, said wall having a minimum casting material thickness of less than 5 mm, also a casting mold for the manufacture of such an engine block, and a method for manufacturing such an engine block.
2. Description of the Related Art
In order to keep the length of an engine block, e.g. a cast aluminum block, as short as possible, efforts are made to arrange the cylinder cavities of a row of cylinders closely adjacent to one another. As a result, the intermediate walls between the cylinders are correspondingly thin. Because of the more closely adjacent combustion chambers and the reduced heat conduction, these thin intermediate walls are exposed to increased thermal stress, especially at the end of the cylinder face closest to the cylinder head. Consequently, it is necessary to provide a cooling duct in the intermediate wall.
It is known in the art that a cooling duct can be produced by machining, namely by cutting into the engine block from the cylinder head seating surface of the block and then sealing the opening shut. This leaves behind a cooling duct that connects sections of a cooling jacket enclosing the row of cylinders, said sections of the cooling jacket extending on opposite sides of the row of cylinders. Alternatively, the engine block is drilled into from the side in order to produce such a cooling duct, and afterwards the drilled passage between the cooling jacket and the outer surface of the engine block must be sealed shut again.